Fluid machine rotor

ABSTRACT

An open-center rotor construction is provided for use in a fluid machine wherein a plurality of separate impeller segments comprising an impeller module are individually removably mounted on an inside rotor wall.

United States Patent 1 Hickey, Jr.

[111 3,804,553 [451 Apr. 16, 1 74 FLUID MACHINE ROTOR [75] inventor: William E. Hickey, Jr., West Hartford, Conn.

[73] Assignee: The Tec Group, Inc., Bloomfield,

Conn.

[22] Filed: Jan. 23, 1973 [21] Appl. No.: 326,129

[52] US. Cl 416/177, 415/122 A, 115/16, 115/34 B, 60/221 [51] Int. Cl. B6311 1/15, FO4d 3/02 [58] Field of Search 415/122 A, 72; 416/176, HY 416/177, 219, 220; 115/34 B, 16, 60/221 [56] References Cited UNlTED STATES PATENTS 1,585,713 5/.1926- Herr et al. 416/220 2,153,055 4/1939 Weissmann 415/122 A 2,605,606 8/1952 Pilz 415/122 A FOREIGN PATENTS OR APPLICATIONS 723,813 2/1955 Great Britain 416/220 750,274 6/1956 Great Britain 115/34 B 81 1,922

Primary Examiner-Henry F. Raduazo Attorney, Agent, or Firm-Prutzman, Hayes, Kalb &

Chilton 57 ABSTRACT An open-center rotor construction is provided for use in a fluid machine wherein a plurality of separate impeller segments, comprising an impeller module are individually removably mounted on an inside rotor wall.

14 Claims, 13 Drawing Figures 4/1959 Great Britain 416/219 MTENTEDAPR 15 19m SHEEI 1 OF 4 QMENTEDAPR 16 i974 5 sum u or 4 FLUID MACHINE ROTOR This invention generally relates to fluid propulsion units and particularly concerns such units of an opencenter axial flow type as shown in copending US. Pat. application Ser. No. 236,263 filed Mar. 20, 1972 in the name of Harvey E. Richter, entitled Axial Flow Unit and assigned to the assignee of this invention.

A primary object of this invention is to provide a new and improved fluid machine rotor of an open-center type having a unique module of removable impeller segments.

Another object of this invention is to provide such a rotor construction wherein the impeller segments are interchangeable as a modular unit with other impeller modules to provide varying characteristics for different applications and which permits removal and replacement of any selected one of the impeller segments of each modular unit.

A further object of this invention is to-provide a new and improved fluid machine rotor construction incorporating individually removable and replacement impeller segments and wherein no fasteners of a conventional threaded type are required and also wherein the entire impeller section of the rotor may be detachably mounted by readily removable keys interposed between impeller segments and releasable spring clips retaining the keys in fixed relation to the rotor.

Still another object of this invention is'to provide a fluid machine rotor of the type described above wherein the individual impeller segments of the rotor may be removed from either axial end of the rotor without requiring dismantling or disassembly of any seals, packings, bearings, gears and other necessary operating components associated with axial flow units of this type. Included in this object is the further aim of providing such. a new and improved rotor wherein any one of the impeller segments may be changed without having to remove the TOtOI' or the fluid machine from its working environment.

A still further object of this invention is to provide a new and improved fluid machine rotor having a significantly simplified design permitting a single open-center fluid machine design'to serve a multiplicity of different fluid flow functions by simply interchanging-removable modular impeller units without disturbing other parts of the machine. t

Another object of this invention isto provide a fluid machine rotor of the type described having a compact rugged construction particularly suited for economical manufacture and quick and easy assembly and disassembly while yet providing high performance operation over an extended service life. I

Others objects will be in part obvious and in part pointed out in more detail hereinafter.

A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth an illustrative embodiment and is indicative of the way in which the principle of this invention is employed.

In the drawings:'

FIG. 1 is a side view, partly broken away and partly in section, showing an axial flow fluid machine incorporating a rotor of this invention;

FIG. 2 is an exploded isometric view of the rotor components; and

FIGS. 3-13 are views, partly in section and partly broken away, taken in a plane normal to the axis of the rotor and sequentially showing the steps in assembling its impeller components.

Referring to the drawings in detail, a preferred embodiment of this invention is shown for illustrative purposes as being incorporated in an axial flow device or fluid machine shown in part and generally designated 10. Machine 10 will be understood to be an opencenter type as described in the: referenced United States patent application Ser. No. 236,263. It is also to be understood that machine 10 while shown as a single stage unit, i.e., with only one impeller stage, could be a multiple stage unit and yet readily incorporate the rotor construction of this invention.

Machine 10 has a drum or rotor shown with its body 12 mounted. for rotation within a cylindrical chamber 13 formed'within a housing generally designated 14. Units of this general type require a suitable power source such as a motor, not shown, for rotating an input shaft, not shown, drivingly connected to a drive gear 16 shown in mesh with a driven ring gear 18 secured by bolts such as at 20 to an outside portion of rotor 12.

As more fully described in copending United States patent application Ser. No. 280,675 filed Aug. 14,

1972 in the name of Harvey E. Richter, entitled Additive Diffuser and assigned to the assignee of this invention, housing 14 provides mountings for bearings such as at 22 supporting rotor 12 for rotation about a central rotational axis generally designated X-X. The foregoing patent application also discloses a particular housing and rotor construction wherein annular end mounting flanges such as 24 are suitably secured to up posite axial ends of housing 14 to maintain seal assemblies, shown in part at 26, in operative association with rotor 12. The glands and packing seals of seal assemblies 26 extend circumferentially about their respective axial end portions on the outer diameter of rotor 12 at its opposite axial ends. The particular rotary drive arrangement and rotor supporting bearing arrangement within housing 14 and the associated seal assemblies 26, etc. are not described herein in detail since such details are not necessary for an understanding of this invention. However, reference is made herein to the noted US. Pat. application Ser. No. 280,675 for an illustration of the general arrangement and type of gear drive, bearing and sealing components which may be installed in fluid machine 10. I

A longstanding difficulty associated with fluidmachines of this general type is the need for periodic removal and replacement of impeller blades and entire.

impeller sections, for any of a variety of reasons, and which is frequently troublesome, time consuming and expensive due to the necessity for dismantling the gear drive, bearing and sealing components of the machine which itself must sometimes be removed'from its environment to provide for replacement of the rotor in its entirety. These problems have been significantly minimized by virtue of this invention wherein a readily interchangeable modular impeller unit 30 is provided for rotor 12 which incorporates a minimum number of operating components and eliminates any necessity whatsoever for disturbing seal assemblies 26, bearings such as at 22 and gear drive 16, 18 of the fluid machine 10 upon replacement of the rotor impellers.

More specifically, each modular impeller unit 30 of this invention includes a plurality of impeller segments such as at 32 which are detachably mounted to the inside cylindrical wall 38 of rotor 12 and are held fixed thereto in circumferentially extending alignment by suitable means in accordance with the teachings of this invention. Three substantially identical impeller segments 32 are illustrated wherein each segment 32 includes an arcuate parti-cylindrical shoe 40 which is constructed to fit precisely into a recess 42 circumferentially extending about the inside wall 38 of rotor 12 in concentric relation to its axis XX. Recess 42 is dimensioned to extend in an axial direction a distance generally equal but slightly greater than the width dimension W of the impeller shoe 40. Additionally, the thickness of each shoe 40 is designed to be equal to the radial dimension of the recess 42. By such construction, the radial location of the surface of each shoe 40 relative to rotor axis X-X is generally the same as that of the inside rotor wall 38, thereby minimizing fluid friction through machine 10.

Each impeller segment 32 has a blade 44 constructed to provide any of a variety of different performance requirements, and the blades 44 are normally cast or welded to their respective shoes 40 to project radially inwardly as an integral portion of segment 32 toward the central rotor axis X--X.

In the preferred embodiment, the arcuate length of the shoes 40 of each impeller segment 32 are dimensioned such that a predetermined spacing may be provided between the shoes 40. More specifically, to permit quick and easy assembly and removal of the impeller segments 32, the total circumferential length of the impeller shoes 40 is sufficiently less than the circumferential dimension'of the inside rotor wall 38 such that, upon circumferentially shifting the shoes 40 into abutting relation (FIG. 9), a circumferential clearance C is formed to permit the segments 32 to be pivoted radially cordingly will not interfere with one another during such swinging movement upon impeller removal. To

further ensure quick and easy, interference-free impeller interchange, the individual impeller segments 32 are contoured and dimensioned such that a projection of the major dimension of each impeller segment in a plane normal to the rotational axis XX of rotor 12 (FIGS. 413) is less than the minimum diameter of the cylindrical inside rotor wall 38 which is preferably of generally uniform diameter.

Individual impeller segments 32 are arranged within rotor recess 42 in circumferentially spaced alignment and are restrained against undesired circumferential shifting by suitable impeller. spacers such as the elongated keys 48 shown in the specifically illustrated embodiment of this invention. Keys 48 not only serve as impeller spacers maintaining the individual impeller segment 32 against circumferential shifting, but, in the preferred embodiment, provide the. additional function of serving as a drive coupling to effect a positive driving connection between rotor 12 and impeller segments 32. As seen in FIG. 3 showing the empty rotor 12, slots are formed in recess 42 to extend axially of rotor 12 along the length of its recess 42 with the slots 50 circumferentially spaced to be located between adjacent impeller segments 32. These slots 50 may be machined, e.g., into the recessed surface of rotor 12, and keys 48 may then be fitted into axial slots 50 (FIG. 11) to serve as a rotary drive transmission member between rotor 12 and the individual impeller segments 32 regardless of the direction of angular movement of rotor 12. When positioned in its slot 50 in driving engagement with the adjacent impeller segments 32, the exposed surface 51 of each key 48 (FIG. 12) preferably conforms to the exposed surfaces of adjacent shoes 40 in smooth continuation therewith and with the internal diameter of the rotor wall 38 to further minimize any frictional drag which would otherwise be created by extension of the keys 48 into the space between the rotor impeller blades 44.

To eliminate any necessity for additional components for holding the impeller segments 32 in position while also ensuring that no inadvertent undesired inward radial movmenet of the individual impeller segments 32 can be effected so long as'the keys 48 are retained in position, the axially extending end walls 46 of adjacent individual shoes 40 of impeller segments 32 are preferably formed in parallel relation to one another, and the key 48 between each adjacent pair of impeller segments 32 is provided with longitudinally extending parallel faces 52 for confronting face-to-face engagement with the end walls 46 of the impeller segments 32.

To hold the above described rotor components in assembly under stationary conditions, a pair of expandible retaining rings or spring clips 54 are shown (FIG. 13) releasably engaged with opposite ends of the keys 48. The preferred embodiment shows the ends of each key 48 stepped to provide a clip receiving notch such as at 56 with the clips 54 engaging the stepped ends of each key 48 and applying a biasing force radially outwardly to retain the keys 48 and therefor the individual impeller segments 32 in assembled relation to the rotor 12. A shoulder 58 is formed at the juncture between the different diameter portions of the rotor wall 38 at opposite ends of recess'42, and the spring clips 54 are dimensioned to closely fit between their respective shoulder 58 and the adjacent circumferentially extending faces 60 of the impeller segments 32 ,to thereby minimize any undesired axial shifting of the impeller segments 32 relative to rotor 12.

At rest, clips 54 hold the modular impeller unit 30 in assembly against gravitational forces, it being understood that the clips 54 are each of enlarged diametrical size in their expanded relaxed state, relative to the size assumed by each clip 54 upon its being positioned within rotor 12 in assembly with the keys 48. As power is applied through suitable means such as the illustrated gear train drive 16, 18, rotary movement is transmitted to the impeller blades 44 through the keys 48 engaged in the slots 50. In motion, the centrifugral forces are the controlling and largest significant forces holding the individual impeller segments 32 in fixed relation to rotor 12.

FIGS. 3-13, sequentially show the steps involved in assembling the impeller components of the rotor 12 of this invention. For clarity of illustration, certain structure has been deleted from the views shown in FIGS. 3-13. Specifically, FIG. 3 shows empty rotor-l2 prior to positioningthe first impeller segment 32 (FIG. 4) within the rotor in position for assembly within recess 42 (FIG. 5). A second impeller segment 32' is shown being inserted into the rotor chamber in FIG. 6 and located (FIG. 7) in position for assembly prior to the third impeller segment 32' being inserted (FIG. 8) and positioned in the recess 42 (FIG. 9). Thereafter, the impeller segments 32 are moved out of abutting engagement from their position in FIG. 9 into symmetrical alignment between axial slots 50 (FIG. 10) whereupon a key such as shown in broken lines at 48' may be disposed between two of the impeller segments and moved radially outwardly to its full line position into its slot 50 (FIG. 11) in operative association with its adjacent impeller segments 32 and rotor 12. All keys 48 are shown in position in FIG. .12 whereupon clips 54 may next be moved intoassembled position in engagement .with the stepped portion of each clip receiving notch 56 at the ends of each key 48 (only one clip 54 being shown in FIG. 13) and interposed between the shoulders 58 of rotor 12 and the confronting circumferentially extending faces 60 of the impeller segment shoes Should it be desired to remove one or more impeller segment 32, disassembly is effected by simply reversing the foregoing sequence of steps.lt is necessary only to remove clips 54'at opposite ends of keys 4 8 and then pull the keys 48 radiallyinwardly to permit the impeller segments 32 to be shifted into position as shown in FIG. 9 and then pivot one of the impeller segments 32 into the rotor chamber as described above for removal and subsequent reassembly. 3

By virtue of the rotor construction of this invention, a wide variety of different fluid functions can be performed by machine 10 with a multiplicity of blade designs which can be, interchangeably installed in. the rotor constructed'in accordance with this invention. Any of a variety of different clips or pins could be used tohold the keys in position, it being unnecessary to maintain the impeller segments in place once the keys are secured in proper position. In addition, the invention can be used with one or more impeller sections of single or multiple stageopen-center fluid machines,

and changing of an entire impeller section or individual impeller segment may be readilyaccomplished from either axial end of the rotor without having to disturb any other operating components and without having to remove the rotor or the machine from its working environment. t I

As will be apparent topersons skilled in the art, varioushmodifications', adaptations and variations of the foregoing specific'disclosure can be made without departing from the teachings of the present invention.

I claim:

1. A fluid machine rotor rotatable on a supporting housing and comprising a body having an open center defined by a cylindrical inside wall surrounding a central rotational axis of the rotor, a plurality of separate impeller segments each having an arcuate particylindrical shoe for detachable mounting on the inside rotor wall and an impeller blade integrally formed on the shoe to project radially inwardly from the shoe toward the rotational axis of the rotor, selectively removable mans establishing .a disengageable driving connection between the shoes of the impeller segments and the rotor, and releasable retaining means for retaining the first mentioned means in fixed relation to the rotor.

2. The rotor of claim 1 wherein the cylindrical inside wall of the rotor is of generally uniform diameter, wherein the separate impeller segments are of substantially identical construction and arranged on the inside rotor wall in circumferentially aligned relation, wherein each of the impeller segments are contoured and dimensioned such that a projection of the major dimension of each impeller segment in a plane normal to the rotational axis of the rotor is less than the minimum diameter of the inside rotor wall, and wherein the total circumferential length of the arcuate shoes of the impeller segments is sufficiently less than the circumferential dimension of the inside rotor wall for selective removal and replacement of any selected one of the impeller segments relative to the rotor.

3. The rotor of claim 1 wherein the shoes of the impeller segments are disposed in circumferentially spaced alignment to one another about the inside wall of the rotor, and wherein said first mentioned means includes a plurality of impeller spacers removably fixed to the rotor and removably interposed respectively between adjacent shoes of the impelller segments for establishin'g' the disengageable driving connection between the shoes of the impeller segmentsand the rotor and for also maintaining the impeller segments against circumferential shifting relative to the rotor.

4. The rotor of claim 1 wherein the plurality of impeller segments comprisean impeller module, said first mentioned means and the retaining means permitting interchange of the-impeller module withother impeller modules of didfferent impeller blade design.

5. The rotor of claim 4 wherein said first mentioned means and the retaining means additionally permits re: moval and replacement of any selected one of the impeller segments of the impeller module.

.6. The rotor of claim 1 wherein the retaining means, said first mentioned means and the impeller segments may be disassembled and reassembled relative to the rotor at either of its axial ends.

7. A fluid machine rotor rotatable on a supporting housing and comprising a body having an open center defined by a cylindrical inside wall. surrounding a central rotational axis of the rotor, aplurality of impeller segments each having an arcuate parti-cylindrical shoe engageable with the inside rotor wall and an impeller blade integrally formed on. the shoeto project radially inwardly from the shoe toward the rotational axis of the rotor, the shoes of the impellersegments each being arranged in. circumferentially spaced alignment to one another on the inside wall of the rotor to be driven thereby, an impeller spacer removably interposed be-- tween the shoes of the impeller segments maintaining the impeller segments against circumferential shifting relative to the rotor, and releasable retaining means securing the impeller spacer in fixed relation to the rotor.

8. The rotor of claim 7 wherein. the parti-cylindrical shoes of the impeller segments are each of a uniform width in a direction extending axially of the rotor, wherein the inside cylindrical wall of the rotor has a concentric recess therein of enlarged inside diameter relative to the inside wall of the rotor, the recess circumferentially extending about the inside rotor wall along an axial length thereof generally corresponding to said width of the impeller segmentsfan d wherein the arcuate shoe of each impeller segment has a circumferentially extending curvature uniformly conforming to the curvature of the recess to be fitted therein upon detachable mounting of the impeller segments relative to the inside rotor wall.

9. The rotor of claim 8 wherein the thickness of the arcuate shoe of each impeller segment corresponds to the difference in radial dimension between the inside rotor wall and the surface of its recess, whereby the internal diameter the assembled segment shoes is generally equal to the internal diameter of the inside rotor wall.

10. The rotor of claim 8 wherein axial slots are formed in the recess of the inside rotor wall along the axial length of the recess, the axial slots being circumferentially spaced apart and located between adjacent impeller segments, wherein the impeller spacer comprises an elongated key removably secured within an axial slot of the recess in co-extending relation thereto and in driving engagement with the adjacent impeller segments, and wherein the retaining means includes a pair of annular spring clips releasably maintaining the keys in operative position against unintended radial ing force urging the keys radially outwardly from the center of the rotor.

12. The rotor of claim 11 wherein the ends of each key are stepped to provide a clip receiving notch, wherein the clips are respectively engaged in the clip receiving notch at their respective ends of the keys and are disposed in close fitting relation between the shoulders at their respective ends of the rotor recess and the shoes of the impeller segments to minimize relative axial movement between the impeller segments and the rotor. j

13. The rotor of claim 10 wherein the shoes of adjacent impeller segments are each formed with axially extending end walls in parallel relation to the end wall of the adjacent impeller shoe, and wherein the keys each have longitudinally extending parallel side walls in confronting face-to-face driving engagement with the rotor surrounding its axial slot and with the parallel end walls of the adjacent impeller shoes for minimizing relative motion between the impeller segments upon rotation of rotor wall. 

1. A fluid machine rotor rotatable on a supporting housing and comprising a body having an open center defined by a cylindrical inside wall surrounding a central rotational axis of the rotor, a plurality of separate impeller segments each having an arcuate parti-cylindrical shoe for detachable mounting on the inside rotor wall and an impeller blade integrally formed on the shoe to project radially inwardly from the shoe toward the rotational axis of the rotor, selectively removable mans establishing a disengageable driving connection between the shoes of the impeller segments and the rotor, and releasable retaining means for retaining the first mentioned means in fixed relation to the rotor.
 2. The rotor of claim 1 wherein the cylindrical inside wall of the rotor is of generally uniform diameter, wherein the separate impeller segments are of substantially identical construction and arranged on the inside rotor wall in circumferentially aligned relation, wherein each of the impeller segments are contoured and dimensioned such that a projection of the major dimension of each impeller segment in a plane normal to the rotational axis of the rotor is less than the minimum diameter of the inside rotor wall, and wherein the total circumferential length of the arcuate shoes of the impeller segments is sufficiently less than the circumferential dimension of the inside rotor wall for selective removal and replacement of any selected one of the impeller segments relative to the rotor.
 3. The rotor of claim 1 wherein the shoes of the impeller segments are disposed in circumferentially spaced alignment to one another about the inside wall of the rotor, and wherein said first mentioned means includes a plurality of impeller spacers removably fixed to the rotor and removably interposed respectively between adjacent shoes of the impelller segments for establishing the disengageable driving connection between the shoes of the impeller segments and the rotor and for also maintaining the impeller segments against circumferential shifting relative to the rotor.
 4. The rotor of claim 1 wherein the plurality of impeller segments comprise an impeller module, said first mentioned means and the retaining means permitting interchange of the impeller module with other impeller modules of didfferent impeller blade design.
 5. The rotor of claim 4 wherein said first mentioned means and the retaining means additionally permits removal and rEplacement of any selected one of the impeller segments of the impeller module.
 6. The rotor of claim 1 wherein the retaining means, said first mentioned means and the impeller segments may be disassembled and reassembled relative to the rotor at either of its axial ends.
 7. A fluid machine rotor rotatable on a supporting housing and comprising a body having an open center defined by a cylindrical inside wall surrounding a central rotational axis of the rotor, a plurality of impeller segments each having an arcuate parti-cylindrical shoe engageable with the inside rotor wall and an impeller blade integrally formed on the shoe to project radially inwardly from the shoe toward the rotational axis of the rotor, the shoes of the impeller segments each being arranged in circumferentially spaced alignment to one another on the inside wall of the rotor to be driven thereby, an impeller spacer removably interposed between the shoes of the impeller segments maintaining the impeller segments against circumferential shifting relative to the rotor, and releasable retaining means securing the impeller spacer in fixed relation to the rotor.
 8. The rotor of claim 7 wherein the parti-cylindrical shoes of the impeller segments are each of a uniform width in a direction extending axially of the rotor, wherein the inside cylindrical wall of the rotor has a concentric recess therein of enlarged inside diameter relative to the inside wall of the rotor, the recess circumferentially extending about the inside rotor wall along an axial length thereof generally corresponding to said width of the impeller segments, and wherein the arcuate shoe of each impeller segment has a circumferentially extending curvature uniformly conforming to the curvature of the recess to be fitted therein upon detachable mounting of the impeller segments relative to the inside rotor wall.
 9. The rotor of claim 8 wherein the thickness of the arcuate shoe of each impeller segment corresponds to the difference in radial dimension between the inside rotor wall and the surface of its recess, whereby the internal diameter the assembled segment shoes is generally equal to the internal diameter of the inside rotor wall.
 10. The rotor of claim 8 wherein axial slots are formed in the recess of the inside rotor wall along the axial length of the recess, the axial slots being circumferentially spaced apart and located between adjacent impeller segments, wherein the impeller spacer comprises an elongated key removably secured within an axial slot of the recess in co-extending relation thereto and in driving engagement with the adjacent impeller segments, and wherein the retaining means includes a pair of annular spring clips releasably maintaining the keys in operative position against unintended radial movement inwardly toward the center of the rotor.
 11. The rotor of claim 10 wherein the spring clips are respectively mounted adjacent shoulders formed at the junctures of the inside rotor wall and its recess, the clips engaging the ends of each key and applying a biasing force urging the keys radially outwardly from the center of the rotor.
 12. The rotor of claim 11 wherein the ends of each key are stepped to provide a clip receiving notch, wherein the clips are respectively engaged in the clip receiving notch at their respective ends of the keys and are disposed in close fitting relation between the shoulders at their respective ends of the rotor recess and the shoes of the impeller segments to minimize relative axial movement between the impeller segments and the rotor.
 13. The rotor of claim 10 wherein the shoes of adjacent impeller segments are each formed with axially extending end walls in parallel relation to the end wall of the adjacent impeller shoe, and wherein the keys each have longitudinally extending parallel side walls in confronting face-to-face driving engagement with the rotor surrounding its axial slot and with the parallel end walls of the adjacent impeller shoes for minimizing relative motioN between the impeller segments upon rotation of the rotor in either angular direction.
 14. The rotor of claim 10 wherein the keys each have an exposed longitudinally extending surface positioned between the shoes and formed in smooth continuation therewith and with the internal diameter of the inside rotor wall. 